Undesirable immune system reactions like autoimmunity and allergies.Encyclopedia Entry for Hypersensitivity :Hypersensitivity pneumonitis. Hypersensitivity pneumonitis usually occurs in people who work in places where there are high levels of organic dusts, fungus, or molds. Long-term exposure can lead to lung inflammation and acute lung disease. Over time, the acute condition turns into long-lasting (chronic) lung disease. Hypersensitivity pneumonitis may also be caused by fungi or bacteria in humidifiers, heating systems, and air conditioners found in homes and offices. Exposure to certain chemicals, such as isocyanates or acid anhydrides, can also lead to hypersensitivity pneumonitis. Examples of hypersensitivity pneumonitis include: Bird fancier's lung: This is the most common type of hypersensitivity pneumonitis. It is caused by repeated or intense exposure to proteins found in the feathers or droppings of many species of birds. Farmer's lung: This type of hypersensitivity pneumonitis is caused by exposure to dust from moldy hay, straw, and grain.Symptoms of acute hypersensitivity pneumonitis often occur 4 to 6 hours after you have left the area where the offending substance is found. This makes it difficult to find a connection between your activity and the disease. Symptoms might resolve before you go back to the area where you encountered the substance. Symptoms may include: Chills Cough Fever Malaise (feeling ill) Shortness of breath Symptoms of chronic hypersensitivity pneumonitis may include: Breathlessness, especially with activity Cough, often dry Loss of appetite Unintentional weight loss.The health care provider will perform a physical examination and ask about your symptoms. Your provider may hear abnormal lung sounds called crackles (rales) when listening to your chest with a stethoscope. Lung changes due to chronic hypersensitivity pneumonitis may be seen on a chest x-ray. Other tests may include: Aspergillosis precipitin blood test to check if you've been exposed to the aspergillus fungus Bronchoscopy with washings, biopsy, and bronchoalveolar lavage Complete blood count ( CBC ) CT scan of the chest Hypersensitivity pneumonitis antibody blood test Krebs von den Lungen-6 assay (KL-6) blood test Pulmonary function tests Surgical lung biopsy.First, the offending substance must be identified. Treatment involves avoiding this substance in the future. Some people may need to change jobs if they cannot avoid the substance at work. If you have a chronic form of this disease, your doctor may recommend that you take glucocorticoids (anti-inflammatory medicines). Sometimes, treatments used for asthma can help people with hypersensitivity pneumonitis.Most symptoms go away when you avoid or limit your exposure to the material that caused the problem. If prevention is made in the acute stage, the outlook is good. When it reaches the chronic stage, the disease might continue to progress, even if the offending substance is avoided.The chronic form of this disease may lead to pulmonary fibrosis. This is a scarring of the lung tissue that often is not reversible. Eventually, end-stage lung disease and respiratory failure can occur.Call your provider if you develop symptoms of hypersensitivity pneumonitis.The chronic form can be prevented by avoiding the material that causes the lung inflammation.Extrinsic allergic alveolitis; Farmer's lung; Mushroom picker's disease; Humidifier or air-conditioner lung; Bird breeder's or bird fancier's lung.Interstitial lung disease - adults - discharge.Bronchoscopy Bronchoscopy Respiratory system Respiratory system.Douglass JA, Sandrini A, Holgate ST, O'Hehir RE. Allergic bronchopulmonary aspergillosis and hypersensitivity pneumonitis.Encyclopedia Entry for Hypersensitivity :Hypersensitivity vasculitis. Hypersensitivity vasculitis, or cutaneous small vessel vasculitis, is caused by: An allergic reaction to a drug or other foreign substance A reaction to an infection It usually affects people older than age 16. Often, the cause of the problem cannot be found even with a careful study of medical history. Hypersensitivity vasculitis may look like systemic, necrotizing vasculitis , which can affect blood vessels throughout the body and not just in the skin. In children, it can look like Henoch-Schonlein purpura.Symptoms may include: New rash with tender, purple or brownish-red spots over large areas Skin sores mostly located on the legs, buttocks, or trunk Blisters on the skin Hives ( urticaria ), may last longer than 24 hours Open sores with dead tissue (necrotic ulcers ).The health care provider will base the diagnosis on symptoms. The provider will review any medicines or drugs you have taken and recent infections. You will be asked about cough, fever, or chest pain. A complete physical exam will be done. Blood and urine tests may be done to look for systemic disorders such systemic lupus erythematosus, dermatomyositis, or hepatitis C. The blood tests may include: Complete blood count with differential Erythrocyte sedimentation rate Chemistry panel with liver enzymes and creatinine Antinuclear antibody (ANA) Rheumatoid factor Antineutrophil cytoplasmic antibodies (ANCA) Complement levels Cryoglobulins Hepatitis B and C tests HIV test Urinalysis Skin biopsy shows inflammation of the small blood vessels.The goal of treatment is to reduce inflammation. Your provider may prescribe aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), or corticosteroids to reduce inflammation of the blood vessels. (DO NOT give aspirin to children except as advised by your provider). Your provider will tell you to stop taking medicines that could be causing this condition.Hypersensitivity vasculitis most often goes away over time. The condition may come back in some people. People with ongoing vasculitis should be checked for systemic vasculitis.Complications may include: Lasting damage to the blood vessels or skin with scarring Inflamed blood vessels affecting the internal organs.Call your provider if you have symptoms of hypersensitivity vasculitis.DO NOT take medicines which have caused an allergic reaction in the past.Cutaneous small vessel vasculitis; Allergic vasculitis; Leukocytoclastic vasculitis.Vasculitis on the palm Vasculitis on the palm Vasculitis Vasculitis Vasculitis, urticarial on the hand Vasculitis, urticarial on the hand.Habif TP. Hypersensitivity syndromes and vasculitis.